Australian powerboat racer Dave Warby is methodically closing in on one of the most dangerous records in sporting history, the unlimited water speed record set by his late father Ken Warby 47 years ago on October 8, 1978.
Warby Motorsport is preparing to return to Blowering Dam in New South Wales on November 8-9, 2025 for their latest testing session. Following a successful engine ground run, the team made a late decision to proceed despite the dam’s water level dropping to 43% capacity. Spirit of Australia II recently achieved 278 mph during testing, and the team faces the ongoing challenge of limited testing opportunities, receiving approximately three sessions per year to develop a boat designed for sustained high speeds across an eight-kilometre course.
The target remains 511.11 km/h (317.60 mph), the speed Ken Warby achieved at the same venue nearly five decades ago.
A Legacy Written in Speed and Sacrifice
Ken Warby’s record remains one of powerboat racing’s most formidable achievements. On that autumn day in 1978, the Australian mechanical engineer piloted his backyard-built Spirit of Australia to become the first person to break the 300 mph barrier on water and survive. His peak speed during the run reached approximately 555 km/h (345 mph) as measured by radar gun.
The record stands as a testament to both engineering brilliance and extraordinary courage. Ken designed and built the original Spirit of Australia in his backyard for approximately $10,000, making him the first and only person to design, build and drive a boat to an unlimited water speed record. The craft was constructed from wood and fibreglass, powered by a military surplus Westinghouse J34 jet engine he purchased at auction for just $265.
Ken Warby died in February 2023 aged 83, but not before working alongside his son to design and build Spirit of Australia II. Dave Warby has continued the project with the original Warby Motorsport team, honouring his father’s legacy whilst facing the stark reality that the unlimited water speed record remains one of the deadliest challenges in powerboat racing.
Seven of the 13 people who have attempted the record since 1930 have died trying. The two official attempts to break Ken Warby’s record both resulted in tragedy. American Lee Taylor perished in 1980 when his rocket-powered Discovery II became unstable at approximately 270 mph on Lake Tahoe. Nine years later, Craig Arfons died when his Rain X Challenger somersaulted at over 300 mph on Lake Jackson, Florida.
Engineering for 370 MPH
Spirit of Australia II represents an evolutionary step from Ken’s original design, incorporating improvements developed through analysis of data from both record runs in 1977 and 1978. The hull stretches 30 feet (9.1 metres), slightly longer than its predecessor, with modified sponsons, altered centre of gravity, updated rudder design and comprehensive safety systems.
The most significant upgrade comes from the powerplant. Spirit of Australia II is powered by a Rolls-Royce Orpheus 803 jet engine sourced from an Italian Air Force Fiat G.91 fighter aircraft. The engine delivers approximately 5,000 pounds of thrust, representing 50% more power than the original Westinghouse J34, whilst weighing 300 pounds less. The turbines spin at 10,000 rpm, generating the equivalent of 10,000 horsepower.
The boat’s theoretical maximum speed stands at 370 mph (595 km/h), though reaching that figure safely requires methodical testing and refinement. Dave Warby, a UIM and APBA accredited reinforced cockpit builder and experienced boat constructor, led the five-year build programme alongside the Warby Motorsport team. The craft weighs 2.5 tonnes and remains within legal trailable width dimensions.
Safety equipment reflects modern standards absent from Ken’s era. The original Spirit of Australia had no seatbelts. Spirit of Australia II features a reinforced carbon-kevlar cockpit, six-point harness, HANS device, on-board air system, GPS tracking, two-way radio communication, three-stage fire extinguisher system and positive flotation capabilities.
The Challenge of Perfect Conditions
Testing Spirit of Australia II presents challenges far different from Ken’s era. Where Ken could arrive at any waterway unannounced and conduct trials, modern regulations require Warby Motorsport to book water space months in advance. Transport for New South Wales issues navigation restriction notices declaring exclusion zones during testing periods, typically between 8:00am and 4:00pm.
Dave Warby has spoken candidly about the difficulties of driving at extreme speeds. During one run exceeding 400 km/h, the hydroplane’s tail began to power slide, demanding split-second corrections whilst maintaining awareness that braking distance at that speed extends approximately 1.8 kilometres.
The steering was extremely sensitive at high speed, so we’ve slowed that down and that’s made the boat easier to drive.
Early testing revealed handling issues that made the boat difficult to control. The rear of Spirit of Australia II exhibited fishtailing behaviour similar to a car in loose gravel. Warby Motorsport addressed the problem through steering geometry modifications and rudder adjustments, vastly improving high-speed stability.
Water conditions prove critical at these velocities. The team discovered that perfectly glassy water creates excessive surface tension, causing the hull to stick then release in a porpoising motion. Ideal conditions require approximately 5 km/h of wind to create a slight ripple that breaks surface tension without generating dangerous chop. Weather patterns across Blowering Dam’s eight-kilometre course can change rapidly, with whitecaps in Yellowin Bay and crosswinds at the centre affecting the boat’s trajectory.
Going that fast, you can see the changes in the water quickly because you’re moving at such a pace. We get a slight crosswind at the centre of the course, and the boat will veer off course. But you can’t really fight the steering on it too much, because if you put too much rudder in on it, it can disrupt the boat.
Incremental Progress Towards History
The path to breaking the record has required patience and precision. The programme faced significant setbacks before recent progress. COVID-19 restrictions halted testing for 18 months. Weather conditions scrubbed four consecutive attempts following the pandemic. A bird strike at over 200 mph in November 2023 damaged the fragile turbine blades, forcing repairs and further delays.
Testing progressed through careful increments during 2024, with the boat reaching 447 km/h before the team identified a critical handling issue that needed resolution.
At speeds above 250 mph, Spirit of Australia II exhibited slight drifting at the rear, a potentially dangerous characteristic that demanded attention before pushing to higher velocities. Over three months, Warby Motorsport developed and fitted a new rear ski designed to improve rear-end stability at extreme speeds.
Testing on September 1, 2025 validated the modification despite challenging conditions. Saturday’s session was cancelled entirely due to high winds and rain across the Alpine region, with snow falling at 600 metres elevation. Sunday morning showed improvement, though winds increased throughout the day and communication issues complicated early runs.
The new rear ski altered how Spirit of Australia II sits on the water, requiring adjustments to the horizontal stabilizer. Initial runs at 150 mph revealed amplified porpoising. Wing adjustments settled the oscillations for a second pass at 210 mph, though the characteristic remained noticeable. Further refinement stabilized the boat at 270 mph across half the course (four kilometres), even with whitecaps forming at the far end.
Warby Motorsport welcomed the presence of Australian motorsport legends Rosco and Cheryl McGlashan during the September testing, along with stuntman Lawrence Legend, a friend of McGlashan. The involvement of experienced speed record veterans underscores the significance of the project and the respect it commands within the specialist community.
The handling and rear of the boat now feel solid and planted. This issue needed to be resolved, and we feel it has been. We can now move forward in a safe, measured manner.
The team conducted several passes between 150-170 mph close to the shore for spectators who had gathered to watch. The standard eight-kilometre record course runs one kilometre offshore, making it difficult for the public to observe testing, prompting the closer demonstration runs.
March 2025 testing at Blowering Dam proved challenging for different reasons. Water levels had dropped to just 30%, significantly limiting the usable course area. Despite the constraints, Warby achieved runs at 220 mph within the available space, demonstrating the boat’s capabilities even under less than ideal conditions.
The team also conducts preliminary testing on the Manning River at Taree, New South Wales, where lower-speed trials evaluate modifications and balance before committing to high-speed runs at Blowering Dam. This two-venue approach allows for development work without consuming precious time allocations at the primary record venue.
The Modern Challenge of Speed Records
Perhaps the greatest obstacle facing Warby Motorsport isn’t technical but bureaucratic. Securing permissions and approvals from authorities to run a jet boat on a body of water represents the biggest hurdle for unlimited speed record attempts in 2025. The team receives roughly three opportunities per year, with each session lasting approximately one and a half days.
The contrast with Ken Warby’s era could not be starker. Throughout the 1930s to 1970s, record challengers could establish camp beside a lake for weeks, testing multiple times per year with minimal oversight. Ken Warby averaged around 10 runs annually over four years, with access to waterways throughout Australia. He would increase speed only when the boat was ready, a methodical approach that nevertheless drew criticism from some observers who failed to appreciate the complexities involved.
Spirit of Australia II faces additional complexity because it’s designed for sustained high-speed running across an eight-kilometre course, not the short bursts of acceleration used in other speed disciplines. As Warby Motorsport notes, achieving good water conditions for 1,000 feet proves relatively straightforward. Maintaining optimal conditions across eight kilometres presents an entirely different proposition, with four different kinds of wind and water conditions possible within a single run.
The team must book testing sessions and secure approvals 10 weeks in advance, forcing them to accept whatever weather conditions materialize on the scheduled days. Ideally, Warby Motorsport requires a week or two of continuous water access to properly fine-tune and dial in the boat’s setup for speeds ranging from 280 mph to 350 mph. Modern regulations and insurance requirements make such extended testing periods nearly impossible to arrange.
The upcoming November 8-9, 2025 testing will proceed despite Blowering Dam water levels at 43% capacity. These constraints underscore the challenge of breaking speed records in an era of heightened regulation and limited access.
The Road Ahead
No official date has been set for the record attempt. Warby Motorsport will only proceed when Spirit of Australia II can safely exceed 317.60 mph during practice runs under optimal conditions. The Union Internationale Motonautique (UIM) requires two runs in opposite directions, with the average speed establishing the record.
The new rear ski installation and handling improvements at 270 mph provide a solid foundation for pushing into higher speed ranges. With drifting issues above 250 mph now resolved, the boat feels planted and stable.
Ken Warby’s record has stood longer than any other unlimited water speed record in history. Donald Campbell’s previous record lasted just three years before Lee Taylor broke it in 1967. Ken Warby then surpassed it a decade later, and his achievement has endured 47 years without a successful challenge. The Australian became a sporting legend, inducted as one of the first 200 members of the Sport Australia Hall of Fame and awarded the MBE in 1978. The original Spirit of Australia remains on display at the Australian National Maritime Museum in Darling Harbour, Sydney.
Whether Dave Warby can safely surpass his father’s achievement will depend on engineering precision, favourable weather, sufficient water levels and the courage required to challenge one of powerboat racing’s most dangerous frontiers. With handling issues resolved and the boat responding well at 270 mph, the pathway to 317.60 mph grows clearer with each test session.
Read about other teams looking to break the record
Date |
Driver |
Boat |
Speed |
Location |
|---|---|---|---|---|
8 Oct 1978 |
Ken Warby AUS Current Record |
Spirit of Australia Jet
|
317.60 mph 511.11 km/h |
Blowering Dam, NSW, Australia |
20 Nov 1977 |
Ken Warby AUS
|
Spirit of Australia Jet
|
288.60 mph 464.46 km/h |
Blowering Dam, NSW, Australia |
30 Jun 1967 |
Lee Taylor USA
|
Hustler Jet
|
285.22 mph 459.02 km/h |
Lake Guntersville, Alabama, USA |
31 Dec 1964 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
276.33 mph 444.71 km/h |
Lake Dumbleyung, Western Australia |
14 May 1959 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
260.35 mph 418.99 km/h |
Coniston Water, England |
10 Nov 1958 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
248.62 mph 400.12 km/h |
Coniston Water, England |
7 Nov 1957 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
239.07 mph 384.75 km/h |
Coniston Water, England |
19 Sep 1956 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
225.63 mph 363.12 km/h |
Coniston Water, England |
16 Nov 1955 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
216.20 mph 347.94 km/h |
Lake Mead, Nevada, USA |
23 Jul 1955 |
Donald Campbell GBR
|
Bluebird K7 Jet
|
202.32 mph 325.60 km/h |
Ullswater, England |
7 Jul 1952 |
Stanley Sayres USA
|
Slo-Mo-Shun IV Prop
|
178.50 mph 287.26 km/h |
Lake Washington, Seattle, USA |
26 Jun 1950 |
Stanley Sayres USA
|
Slo-Mo-Shun IV Prop
|
160.32 mph 258.02 km/h |
Lake Washington, Seattle, USA |
19 Aug 1939 |
Malcolm Campbell GBR
|
Bluebird K4 Prop
|
141.74 mph 228.11 km/h |
Coniston Water, England |
2 Sep 1937 |
Malcolm Campbell GBR
|
Bluebird K3 Prop
|
129.50 mph 208.41 km/h |
Lake Maggiore, Italy |
1 Sep 1937 |
Malcolm Campbell GBR
|
Bluebird K3 Prop
|
126.32 mph 203.29 km/h |
Lake Maggiore, Italy |
20 Sep 1932 |
Gar Wood USA
|
Miss America X Prop
|
124.86 mph 200.94 km/h |
St. Clair River, Michigan, USA |
18 Jul 1932 |
Kaye Don GBR
|
Miss England III Prop
|
119.81 mph 192.82 km/h |
Loch Lomond, Scotland |
5 Feb 1932 |
Gar Wood USA
|
Miss America IX Prop
|
111.71 mph 179.78 km/h |
Indian Creek, Miami, USA |
31 Jul 1931 |
Kaye Don GBR
|
Miss England II Prop
|
110.22 mph 177.39 km/h |
Lake Garda, Italy |
20 Mar 1931 |
Gar Wood USA
|
Miss America IX Prop
|
102.26 mph 164.57 km/h |
Indian Creek, Miami, USA |
13 Jun 1930 |
Henry Segrave GBR
|
Miss England II Prop
|
98.76 mph 158.94 km/h |
Windermere, England |
23 Mar 1929 |
Gar Wood USA
|
Miss America VII Prop
|
93.12 mph 149.87 km/h |
Indian Creek, Miami, USA |
4 Sep 1928 |
George Wood USA
|
Miss America VII Prop
|
92.84 mph 149.41 km/h |
Detroit River, Michigan, USA |
15 Sep 1920 |
Gar Wood USA
|
Miss America Prop
|
77.85 mph 125.29 km/h |
Detroit River, Michigan, USA |
19 Sep 1919 |
Casey Baldwin USA
|
HD-4 Hydrofoil Prop
|
70.86 mph 114.04 km/h |
Bras d’Or Lake, Nova Scotia, Canada |

